Dear Lifehacker, I’m a student using a MacBook Pro for uni on which I’ve got Mac OS X & Windows 7 dual booted. I’m constantly switching between the two depending on what I need to do (though Windows is my preferred OS). Recently I’ve noticed that the battery lasts longer on the OS X side than it does on the Windows 7 side, even when only browsing the internet. Why is this? Does this mean that OS X is more energy efficient (& hence environmentally friendly) than Windows?
I’ve even got Aero turned off but Windows still eats almost four hours of the battery more than OS X! I’m willing to make the full switch to OS X & virtual machine the Windows programs I need if it is. You know, doing my part for the environment. Thank you for your help, Energised Student
Picture by Ed Yourdon
Dear Energised Student,
The answer to your question is twofold: yes, your MacBook is pretty much guaranteed to do a better job of power management and offer longer battery life when you're running Mac OS X than when you're running Windows. But that doesn't mean that Windows itself is inherently less energy-efficient than Mac OS X. It means that Windows is less energy-efficient when running on a MacBook, which isn't surprising.
Apple controls both the coding of OS X and the components used in a MacBook, so it can design them to work extremely efficiently together. When it comes to running Windows, while the Mac can do this pretty well, it's never going to receive the same degree of optimisation attention from Apple engineers. (By the same token, while you can convert a PC into a Hackintosh, you're unlikely to get the same level of battery performance as you would if you stuck with Windows.)
So if energy use (and battery life) is a concern, what should you do? If sticking with the MacBook is your preferred route, then cutting back on the Windows apps you use will definitely pay dividends. Running Windows apps in a virtual machine may improve battery performance, but because running VMs places extra demands on your processor, I imagine you won't get quite as good results as you would running purely native apps, and you might not notice much difference relative to your current dual-booting strategies. The only way you'll know is if you try, though.
If you do want to run a lot of Windows apps, then your best bet would be to switch to a dedicated Windows notebook, where you'll likely find that your battery performance will be much improved because the hardware optimisation will work more effectively.
If readers have their own strategies for maximising battery life on a MacBook also running Windows, we'd love to hear them in the comments.